The search giant’s display revenues in 2012 will jump almost 39%, to $2.31 billion, while Facebook’s will rise 24% to $1.73 billion and Yahoo’s revenues barely budge to hit $1.39 billion. Overall, display ad revenues will rise almost 22% this year, to about $15 billion, thanks to Google’s and Facebook’s growth, the continuing explosion in ad inventory thanks in part to mobile advertising, and more spending on video ads, especially on YouTube.

But that number is down a bit from eMarketer’s previous forecast because of lower display ad prices on ad networks and continuing wariness by big brands to up their display spend significantly. Google and Facebook combined will account for nearly 30% of display ad revenues this year, rising to 37% in 2014.

What’s more, according to eMarketer, Google will lengthen its lead in the next couple of years in these banner, video, and social ads that are the mainstay of most commercial websites, reaching $4.4 billion in 2014 to Facebook’s $3.2 billion and a moribund Yahoo’s $1.5 billion. Microsoft and AOL also will continue to see relatively flat revenues.

What’s going on here? For one, Google’s display-ad engine has begun to rev, thanks to its YouTube video site, its mobile ads, and its DoubleClick ad-buying and ad exchange business. At the same time, Facebook has seen its growth slow recently, raising questions in the minds of investors about the effectiveness of its social ads and its relative lack of mobile ads. Earlier this year, eMarketer had forecast that Google wouldn’t capture the display lead until next year. …

This is a little inside-ad-tech-baseball, so bear with me. But essentially, Google is gradually refining the pieces of what it hopes will be something of an operating system for online advertising, not just the search ads it dominates but the picture- and video-based ads that support most websites:

* It’s close to integrating key pieces of ad buying and creation systems that it built or acquired in recent years. For one, the ad buying system DoubleClick Bid Manager–the “demand-side platform” formerly known as Invite Media that Google acquired two years ago–will move out of beta test mode and become available to all customers next month. Google says improvements in the underlying technology infrastructure have reduced the time it takes to connect with various ad exchanges, allowing beta customers to access 16% more ad inventory on the thousands of websites that use DoubleClick. …

For years, advertisers have been wondering when Facebook would create its own ad network like Google’s AdSense, which syndicates ads across thousands of websites. Google grossed more than $10 billion last year on that business.

Now we’re getting a hint that Facebook may be preparing to flip the switch on its own ad network. Today, the social network said it’s testing Facebook ads that use its own data to target ads to Facebook users as they land on other websites and on mobile apps.

The company isn’t calling it an ad network, because for now it’s just a test. A Facebook spokesperson says it’s using outside Apple iOS and Android ad exchanges to run the test, not its own technology, but it is an ad network in function. So you can bet that if it works–and Facebook hasn’t decided how long the test will be conducted–a bona fide Facebook ad network won’t be far behind.

Details are sparse, since Facebook isn’t saying which advertisers, publishers, and mobile ad exchanges are involved in the test. It’s a “very small number” of each, says Facebook. Most of the ads, which will be standard banners and “interstitials” that run just before a web page loads, will likely be for app installations. The main value for marketers and apps is that Facebook’s user data on age, gender, and “likes,” offered freely by its members, is usually considered to be more accurate than other kinds of data collected on people as they browse online.

This is the latest and still relatively limited move by Facebook to expand its ad business beyond Facebook.com. In June, it started placing ads on social games site Zynga.com, the social games siteed on Facebook. The same month, it introduced the Facebook Exchange, which lets marketers target customers and prospects with ads on Facebook using their own data, not just Facebook’s.

This is also a further push into mobile advertising, the lack of which has been a thorn in Facebook’s side since its less-than-blockbuster initial public offering in May. Separately today, Facebook announced a new version of its Pages Manager mobile app that will let businesses buy a new mobile ad format called promoted posts directly from their mobile phones.

Facebook CEO Mark Zuckerberg said last week that he thinks mobile will be even bigger for Facebook’s ad business than the Web. Today’s announcement shows it’s more than just talk.

But investors and advertisers will still have to wait awhile longer for the full-fledged Facebook ad network–and the big boost in revenues that they hope will come with it.

Even though I recommended that most people not buy Apple’s just-launched iPhone 5 last week, I’m the last one to be surprised that my sage advice was largely ignored. Apple just announced that 2 million people pre-ordered its latest and greatest smartphone in the first 24 hours. I fully expected the new iPhone to be enormously popular because, well, Apple’s major products almost always are.

I still stand by my advice, however, despite the record pre-orders. I continue to think that most people who own a smartphone purchases in the last year or two have no overriding reason to buy a new one so soon, and some good reasons not to. Nonetheless, it’s worth asking why so many people did anyway–and why a third of Americans want one:

2) The iPhone 5 is the right decision for a certain portion of smartphone buyers–easily millions in a market of hundreds of millions of them. As I wrote before, if you have a phone that’s more than a couple of years old, technology advances mean it’s about time to get a new one, and the iPhone 5 is a great choice, if not the only good one.

3) The new iPhone is a clear advance over the iPhone 4S, even if it’s not a revolutionary advance. It has high-speed 4G data capability, its screen is larger, and it’s noticeably lighter. All good.

4) Media hype. The dirty little secret of tech media is that anything written on Apple gets a lot of readership, even if it’s not positive–though it was hard to be too awfully negative on the iPhone 5. Sure, the Samsung Galaxy S III and other smartphones have more bells and whistles, but not enough more to really shame the iPhone 5, and the S III has its own shortcomings as well. And so that mostly positive iPhone coverage drove more interest in the new Apple phone, and record pre-orders. Nothing new here, but this dynamic undeniably gives Apple products a leg up on every other rival.

5) People don’t always buy in an economically rational way. If you’ve got a 4S with an unlimited data plan, you’ll be spending on a new device and paying more for data to boot if you buy the iPhone 5–a device that for all its improvements probably won’t change your life, your productivity, or your mobile communications or entertainment very much. Nothing new here either, but I still contend that many of the tens of millions of people who will snap up the iPhone 5 in coming months will fit this profile. And that’s not counting idiots who can’t tell the difference between iPhone models.

6) I’m actually an idiot, so why would anyone take my advice anyway? OK, I don’t believe that, but clearly a lot of commenters on my previous post do, so I feel obligated to mention the possibility that I don’t know what I’m talking about. Besides, I wanted to provide one answer that would satisfy all those rabid Apple fanboys.

To hear Facebook tell it, its Sponsored Stories, which let marketers tap people’s comments or “likes” of products to create an ad for their friends, are the future of advertising. And they’re apparently doingquitewell for the social network.

But when it comes to technology products in particular, which account for more than a fifth of online advertising, friends, social networks, and even any kind of advertising all rank well below articles by experts in the field when it comes to consumers researching what to buy. That’s according to a recent survey by tech blog network NetShelter Technology Media, for which audience tracker Crowd Science polled more than 1,000 people on 74 tech blogs such as 9to5Mac, Crackberry.com, and MacRumors.

Some tidbits from the survey:

* 85% of respondents said the most useful and influential online content when they’re considering buying tech products are articles, reviews, blog posts, and videos by experts. That’s far more than 35% who cited brand content, 33% who trust family and friends, and just 6% who are most influenced by advertising.

* 70% of people said they don’t turn to Facebook, Twitter, or other social media when they want to buy a tech product. Only 9% consult a Facebook brand page, 4% consider brand “likes,” and 8% pay attention to likes or recommendations from Facebook friends.

* Email is the preferred way 69% of people like to share articles and reviews, while 37% use Facebook, 15% use Twitter, and 20% use LinkedIn. …

With Twitter apparently on a path to profits, or at least revenues, two of its cofounders are now on to other things. Biz Stone’s and Evan Williams’ new company is Obvious, whose motto on its spare website is “We do various things.” A bit more specifically (but not much), Obvious’ goal is to “build systems that help people work together to make the world a better place.” Its first effort, called Medium, might be viewed as Twitter 2.0, seeking to figure out what to do with the firehose of information Twitter has helped create.

In a “fireside chat” with Hunter Walk, a Google director of product management working at YouTube, at the TechCrunch Disrupt conference in San Francisco today, Stone and Williams fleshed out their vision, admitted they didn’t get everything right at Twitter, and offered advice on how to build Internet companies today:

Q: You don’t still work at Twitter, right?

Williams: I’m on the board, but we don’t work at Twitter.

Q: It’s not an incubator, not an investment fund, and you’re building Medium. So what is Obvious?

Stone: It’s an excuse for me and Ev to work together. Really cool, good stuff comes from an organic atmosphere of working on things. We do whatever it takes to help people and projects philosophically aligned with us succeed.

We have marketing capabilities, design and engineering prowess, and money, and we deploy them wherever it makes sense.

A: Now you are older and wiser and wealthier, and parents. How does that change how you run a company?

Williams: I tried to be a ski bum when I left Twitter, but it didn’t work. We’re driven to do interesting things in the world. We decided to let it evolve as the products evolve, figure it out organically as we go. That’s satisfying. It’s a hell of a lot more fun than skiing every day.

Q: The first product you’ve come out with is Medium.

Williams: We came out with a preview, not a real product yet, a few weeks ago. We have a team of engineers working on it every day.

Medium is essentially a publishing platform, along the lines of what we’ve done before, with Xanga and Blogger. We’ve been obsessed with the democratization of media on the Internet. We just thought there’s still more stuff to do.

Q: Only a select few can publish on Medium. Why?

Williams: We want to help high-quality content succeed and get attention. Not everybody can write. It’s not to limit who can publish. It just happens to be we launched in private beta. It’s hard to throw open the doors in closed beta. It’s definitely not the ethos of Medium to be closed in any way.

We’re just hours away from what will certainly be one of the most massive hypefests of the year: the introduction of Apple’s newest iPhone. Even without the benefit of Steve Jobs to add that extra touch of magicreality distortion to the proceedings in San Francisco, the entire tech world will see a plunge in productivity for several hours starting at 10 a.m. Pacific while they watch and chew over the launch of what is all but now confirmed to be called the iPhone 5.

No doubt Apple will sell a ton of the new iPhones. Indeed, though I find this hard to believe, iPhone sales could even add a big boost to this year’s Gross Domestic Product. Diehard Apple fans, and there are millions upon millions of them, won’t be able to resist lining up at Apple stores the night before they become available to be among the first to buy the latest and greatest iPhone.

But you shouldn’t be one of them. Here’s why I think most of you–not all, but most–would be better off not buying the new iPhone:

* It probably won’t be revolutionary. I know–blasphemy! The many leaks of what the new one will look like and the way it will work indicate the new iPhone will, of course, be thinner and faster and sport a bigger screen. So what else is new?

And think about the last time. The iPhone 4S had Siri, the voice assistant that was supposed to revolutionize the way we interact with devices and, oh, by the way, kill Google search. It did neither (though ask me again in a few years, as Siri no doubt steadily improves).

Anyway, let’s face it, smartphones in their current incarnation may not get much better fundamentally. As Steve Shankland at CNET recently pointed out, we’re in an era of incremental refinement more than revolutionary change. At some point, Apple may well come up with yet another product that actually resets the standard for computing and communication devices. But by all reports, the new iPhone isn’t that product. Simply put, you don’t need to own this phone.

* There’s always a risk that something won’t work quite right on the new model, leaving you with buyer’s remorse. Apple’s better than most at avoiding this sort of thing. But remember that faulty antenna in the iPhone 4 two years ago? Update: One word: Maps.

* The older iPhones are still great. Even though some reviewers criticized Apple for touting a machine that didn’t provide many advances, such as a larger screen, the iPhone 4S last year still was widely seen as the best iPhone yet, and still the best overall on the market.

* You will get several of the benefits of the new iPhone just by installing iOS 6–for free. No big screen, no fast LTE data, of course–two biggies, to be sure. But you won’t be left with lagging services like you do with many Android phones that can’t upgrade to the latest OS.

* The older iPhones are also cheap–or free! For one thing, used iPhones are flooding the market as people get ready to buy the new one. Last month, Sprint Nextel and even Apple itself discounted the iPhone 4S, and it doesn’t stretch the imagination to think that when the new model appears, prices for older iPhones will fall across the board. When the iPhone 4S came out, the iPhone 4’s price fell to just $100 and the 3G model was (and still is) free with at AT&T contract. If the pattern holds, doesn’t a free iPhone 4 sound pretty sweet?

* If you go with an older model, you can also save bigtime on service plan costs. If you go with a prepaid carrier such as Virgin Mobile or Cricket, you have to pay more for the phone, but over a couple of years, their lower-cost data plans save hundreds of dollars. It’s not clear whether similar deals will be offered with the new iPhone, but it appears unlikely at the outset–so your only way to get those savings is to go with an older model.

* You may have fewer unlimited-data plan options with the new iPhone. Verizon and AT&T have ended their unlimited-data plans, so that’s not new. But on existing phones and contracts, they’re grandfathered in, a significant reason to think twice about an iPhone purchase that would require you to switch carriers. Sprint may offer an unlimited-data plan, but that means switching carriers if you’re not already on it.* There are–yes–other smartphones out there.Android phones such as Samsung’s Galaxy S III, and even some Windows 8 phones such as Nokia’s Lumia 920, get rave reviews. …